Modular getters in vacuum enclosures and getters using different materials

Abstract

Some embodiments include an apparatus comprising: a vacuum enclosure having an opening; a support structure disposed within the vacuum enclosure, the support structure having a first portion attached to the vacuum enclosure at the opening; and a second portion extending within the vacuum enclosure; and a plurality of getters disposed on the second portion of the support structure.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Patent Application No. 18 / 176,458, filed February 28, 2023, which is hereby incorporated by reference in its entirety and for all purposes.

[0002] Vacuum enclosures, and specifically vacuum enclosures for x-ray sources, may rely on a particular vacuum level during operation. Leaks or other molecular sources within the vacuum enclosure can cause the pressure within the vacuum enclosure to increase. Getters may be used to adsorb or absorb generated atoms and molecules to maintain the vacuum level. [Brief explanation of the drawings]

[0003] [Figure 1A] FIG. 1 is a block diagram of an apparatus including a modular getter according to some embodiments. [Figure 1B] FIG. 1 is a block diagram of an apparatus including a modular getter according to some embodiments. [Figure 1C] FIG. 1 is a block diagram of an apparatus including a modular getter according to some embodiments.

[0004] [Figure 2] FIG. 1 is a block diagram of an apparatus including a modular getter according to some embodiments.

[0005] [Figure 3A] 3 is a cross-sectional view of the getter of FIG. 2 according to some embodiments. [Figure 3B] 3 is a cross-sectional view of the getter of FIG. 2 according to some embodiments.

[0006] [Figure 4] FIG. 1 is a block diagram of an apparatus including a modular getter with an extendable support structure, according to some embodiments.

[0007] [Figure 5A] FIG. 1 is a block diagram of an apparatus including a modular getter with electrical connections, according to some embodiments. [Figure 5B] FIG. 1 is a block diagram of an apparatus including a modular getter with electrical connections, according to some embodiments.

[0008] [Figure 6] FIG. 1 is a block diagram of an apparatus including a modular getter with multiple electrical connections, according to some embodiments.

[0009] [Figure 7] FIG. 1 is a block diagram of an apparatus including a modular getter with shielding, according to some embodiments.

[0010] [Figure 8] FIG. 1 is a block diagram of an apparatus including multiple modular getters, according to some embodiments.

[0011] [Figure 9] FIG. 1 is a block diagram of an x-ray source having multiple getters, according to some embodiments.

[0012] [Figure 10A] 1 is a flowchart of a technique for manufacturing a device, according to some embodiments. [Figure 10B] 1 is a flowchart of a technique for manufacturing a device, according to some embodiments.

[0013] [Figure 11] FIG. 1 is a block diagram of an x-ray imaging system according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0014] Embodiments relate to modular getters within a vacuum enclosure and getters using different materials. The getters include materials capable of adsorbing gases. The getters can be placed within the vacuum enclosure to capture gases, such as gases generated during bakeout or other manufacturing operations or gases remaining after a vacuum is pulled. As described in more detail below, devices can include multiple getters and multiple getters using different materials.

[0015] 1A-1C are block diagrams of an apparatus including a modular getter according to some embodiments. Referring to FIGS. 1A and 1B, the apparatus 100a includes a support structure 102. A plurality of getters 106 are disposed on a second portion 102b of the support structure 102. The number of getters 106 may be N, where N is any integer greater than 1. The getter 106 is a component configured to capture atoms or molecules (found in a gas). Trapping includes collection, adsorption, or absorption of atoms and molecules that may be found in a gas. The getter 106 may capture atoms or molecules on the inside 140b of the vacuum enclosure 140. The atoms and molecules may be collected or adsorbed on the surface of the getter 106, or the atoms or molecules may be absorbed or diffused within the bulk material of the getter 106.

[0016] In some embodiments, the apparatus 100a includes a vacuum enclosure 140 configured to separate an interior 140b having a vacuum from an exterior 140a. The vacuum enclosure 140 includes an opening 140c. The support structure 102 and attached components can be configured to be insertable into the interior 140b through the opening 140c. For example, the dimensions of the getter 106 can be selected so that the getter 106 can pass through the opening 140c from the exterior 140a of the vacuum enclosure 140. For example, the opening 140c can be circular. The getter 106 can be cylindrical with a diameter smaller than the diameter of the circular opening 140c. In other examples, the opening can have a different shape, such as a polygonal shape, and the getter 106 can have corresponding features and dimensions smaller than the opening 140c.

[0017] The support structure 102 includes a first portion 102a configured to be attached to the vacuum enclosure 140 and a second portion 102b extending inside 140b of the vacuum enclosure 140 when attached to the vacuum enclosure 140. While the interface between the first portion 102a and the vacuum enclosure 140 at the opening 140c is illustrated as a butt joint, in other embodiments, the first portion 102a may be attached to the vacuum enclosure 140 using a different interface. Furthermore, while the interface between the first portion 102a and the second portion 102b is illustrated as being perpendicular or orthogonal to one another, in other embodiments, the second portion 102b may be at an angle relative to the first portion 102a. FIG. 1A shows the support structure 102 and associated components positioned outside 140a of the vacuum enclosure 140 prior to insertion. FIG. 1B shows the support structure 102 mounted in a vacuum enclosure 140 with at least some of the associated components disposed on the interior 140b.

[0018] In some embodiments, the support structure 102 is electrically connected to the vacuum enclosure 140. The support structure 102 may be at the same electrical potential as the vacuum enclosure 140. For example, the support structure 102 may be welded to a metal wall of the vacuum enclosure 140 at the opening 140c.

[0019] In some embodiments, the apparatus 100a allows for modular getters 106. For example, each of the getters 106 may be the same type of getter. The getters 106 may be purchased in bulk to reduce costs. However, different vacuum enclosures 140, vacuum enclosures 140 with different volumes, different applications using the vacuum enclosures 140, or the like may require different capacities, different preferred species, or different activation temperatures of the getters 106. Capacity refers to the amount or quantity of atoms or molecules that the getter 106 can capture. Species refers to the material or structure of the getter 106. For example, some getters 106 may have materials that prefer air components and noble gases, while others may prefer oxygen. Activation temperature refers to the temperature at which the getter 106 begins to substantially capture atoms or molecules. For example, some getter 106 materials can be activated at approximately 1600-2000 degrees Celsius (°C), while others can be activated at different temperatures, such as approximately 700-1300°C. In some embodiments, the getter 106 can be activated at a temperature below the bake-out temperature of the vacuum enclosure 140. Such getters 106 can be activated during the bake-out process and may not require a separate activation step. The getter 106 may have a preferred activation temperature that enables the getter 106 to capture molecules and atoms from the surrounding vacuum at its associated maximum pumping speed and capacity. However, the getter 106 may be partially activated. For example, the getter 106 may be heated to a lower temperature, thereby reducing its capacity and pumping speed. Once fully or partially activated, the getter 106 may remain activated even if the temperature drops below the activation temperature. The getter 106 may remain activated until the getter 106 has captured its associated capacity of atoms or molecules. The getter 106 may become inactive when the getter 106 may be unable to capture additional atoms or molecules, or the amount that can be captured may be significantly reduced. The getter may be reactivated. For example, the getter 106 may be heated to cause the getter 106 to eject a portion of the captured atoms or molecules.These atoms or molecules can be pumped out of the vacuum enclosure 140 by a background pumping system such as a turbo pump, ion pump, or the like. In this case, the getter 106 may have the capacity to capture additional atoms or molecules. A single getter may be used per situation; however, this may increase the number of components, part count, or the like for production and maintenance of the associated system. On the other hand, using a modular getter device 100a can reduce the number of different components, part count, or the like. In particular, in situations where a smaller capacity is required, fewer getters 106 can be installed on the support structure 102; on the other hand, if a larger capacity is required, more getters 106 of the same type can be installed on the support structure 102. Therefore, custom getters are not required for different applications. Rather, assemblies 100a with getters 106 for different applications can be created from the same components, such as the same support structure 102 or constituent components, and a desired number of individual getters 106. Although embodiments include multiple getters 106 , in some embodiments, there may be only a single getter 106 even though the support structure 102 has the capacity for multiple getters 106 .

[0020] Additionally, the apparatus 100a with the modular getter 106 may have fewer electrical feedthroughs, fewer penetrations in the vacuum enclosure 140, and / or fewer seams, welds, or other penetrations in the vacuum enclosure 140. The number of failure points that can cause vacuum leaks may be reduced. Because such structures can be relatively complex and expensive, reduced electrical feedthroughs may reduce costs.

[0021] 1C , in some embodiments, the vacuum enclosure 140 includes a major outer surface 140d. A protrusion 140e of the vacuum enclosure may extend toward the exterior 140a. The walls of the protrusion 140e may surround the support structure 102 and the getter 106 within a region 142 of the interior 140b. The region 142 may be continuous with the remainder of the interior 140b through an opening 140f.

[0022] A conductive plate 107 may be disposed at an end of the support structure facing the first portion 102a. The conductive plate 107 may be electrically connected to the first portion 102a and the vacuum enclosure 140. The conductive plate 107 may be disposed at or near the opening 140f. The conductive plate 107 may include an opening 107a. The opening may allow gas present in the interior 140b to pass into the region 142 and be captured by the getter 106.

[0023] The conductive plate 107 may be positioned at the end of the support structure 102 at the opening 140f so that the electric field strength around the opening 140f is as uniform as possible with the electric field along the inner surface of the vacuum enclosure. For example, if the vacuum enclosure 140 and the conductive plate 107 are at the same or similar potential, the electric field in the region will be relatively low, even if a higher electric field strength exists in the remainder of the interior 140b. As a result, the likelihood of arcing near the getter 106 may be reduced.

[0024] 2 is a block diagram of an apparatus including a modular getter according to some embodiments. In some embodiments, apparatus 100b may be similar to other apparatuses 100 described herein. Apparatus 100b may include N getters 106, although, by way of example, only two getters 106 will be used.

[0025] The device 100b includes at least one rigid component 108 and at least one resilient component 110. The rigid component 108 is a component that is rigidly attached to the support structure 102. In some embodiments, the rigid component 108 may include a washer, nut, protrusion, or the like, on the support structure 102. Each of the getters 106 is in contact with a corresponding rigid component 108. In this example, getter 106-1 is in contact with rigid component 108-1, and getter 106-2 is in contact with rigid component 108-2.

[0026] The elastic component 110 is a component that can accommodate changes in size and attempts to return to its original size. In some embodiments, the elastic component 110 includes a spring, a compressible structure, or the like. The movement of each of the getters 108 is constrained, at least in part, by the corresponding elastic component 110. In this example, getters 106-1 and 106-2 are in contact with the elastic component 110. However, in other embodiments, each getter 106-1 and getter 106-2 may be associated with a different elastic component 110. Furthermore, in other embodiments, the getter 106 may not be in direct contact with the corresponding elastic component 110. The getter 106 and the corresponding elastic component 110 may be separated by another component that may be movable relative to the corresponding rigid component 108, such as a washer disposed between the getter 106 and the corresponding elastic component 110 that is movable along the support structure 102.

[0027] Thus, the elastic component 110 applies pressure to the getter 106. The getter is pushed into the corresponding rigid component 108 and is held substantially in place. The getter 106 can be held in place during handling, insertion, welding, operation, or the like. The elastic component 110 can accommodate thermal expansion of the getter 106, the support structure 102, or the like.

[0028] 3A-3B are cross-sectional views of the getter of FIG. 2, according to some embodiments. FIG. 3A is cross-section A of FIG. 2, and FIG. 3B is cross-section B of FIG. 2. Referring to FIGS. 2-3B, in some embodiments, a resilient component 110 can allow atoms or molecules to reach the interior surface of the getter 106. In this example, the getter 106 has a generally cylindrical shape with an opening that accommodates the support structure 102. However, at cross-section A, the getter 106-2 can contact the support structure 102. While the getter 106-2 is illustrated as contacting the support structure 102 around the entire periphery of the support structure 102, in other embodiments, the amount of contact may be less. The pressure of the resilient component 110 can push the getter 106-2 toward the rigid component 108-2, restricting the movement of atoms or molecules into the interior opening of the getter 106-2.

[0029] However, at cross section B, the diameter of the opening is larger. As a result, the surface of the getter 106-2a is offset from the surface 102c of the support structure 102. The elastic component 110 may allow atoms or molecules to enter the opening. As a result, a larger surface area of ​​the getter 106-2a is available to capture atoms or molecules from the interior 140b of the vacuum enclosure 140.

[0030] 4 is a block diagram of an apparatus including a modular getter with an extendable support structure, according to some embodiments. The apparatus 100c can be similar to the apparatus 100 described herein. The extendable support structure 102 includes multiple separate second portions 102b that can be connected to each other. As an example, two second portions 102b-1 and 102b-2 are shown, although in other embodiments, the number of second portions 102b can be more than two.

[0031] The second portion 102b is connectable to extend the support structure 102 so that it can accommodate more getters 106. By way of example, four getters 106-1 to 106-4 are shown, although in other embodiments the number of getters 106 may be different.

[0032] In some embodiments, the second portion 102b is connectable by a threaded interface 112. The second portion 102b can include a complementary threaded interface 112, such that the second portion 102b can be directly attached. However, in other embodiments, the second portion 102b can be attached differently. For example, the second portion 102b can be attached through a rigid component 108, such as a nut. Although the threaded interface 112 is illustrated as being offset from the rigid component 108-2, in some embodiments, the interface between the second portions 102b-1 and 102b-2 can be coincident with the rigid component 108-2, can include the rigid component 108-2 as part of the connection between the second portions 102b-1 and 102b-2, or the like.

[0033] 5A and 5B are block diagrams of an apparatus including a modular getter with electrical connections, according to some embodiments. Referring to FIG. 5A, apparatus 100d can be similar to apparatus 100 described herein. However, apparatus 100d includes a getter 106 having a heating element 122. In some embodiments, each of the getters 106 includes a heating element 122. In other embodiments, fewer than all of the getters 106, including only one, include a heating element 122.

[0034] The structural support 102 includes multiple feedthroughs 120. In this example, the structural support 102 includes two feedthroughs 120 that penetrate the first portion 120a. The feedthroughs 120 and the heating elements 122 are electrically connected. In this example, the heating elements 122 are electrically connected in series. When the heating elements 122 are electrically connected in series, each heating element 122 can receive substantially the same current. As a result, the getter 106 can be heated substantially uniformly. Furthermore, the voltage across the feedthrough 120 can increase with more getters 106 and heating elements 122, while the current will remain substantially the same. Thus, a feedthrough 120 with a particular current rating can be used for any number of getters 106 and associated heating elements 122 in terms of current handling capability. The voltage can increase with additional getters 106. However, the feedthrough 120 can be capable of accommodating the higher voltage associated with multiple series-connected heating elements 122. Furthermore, by coupling multiple heating elements 122 in series to two feedthroughs, the cost of the apparatus 100d may be reduced. The feedthroughs 120 and associated penetrations in the vacuum enclosure 140 may be relatively expensive. By coupling multiple getters 106 and associated heating elements 122 to fewer feedthroughs 120, rather than having one pair of feedthroughs 120 for each getter 106 and heating element 122, costs are reduced. Furthermore, the additional feedthroughs 120 require less area on the vacuum enclosure 140, resulting in a more compact structure. Furthermore, fewer feedthroughs means fewer penetrations in the vacuum enclosure 140, which may reduce the number of potential failures.

[0035] In some embodiments, the getter 106 and heating element 122 are electrically floating with respect to the vacuum enclosure 140. That is, the voltage across the feedthroughs 120-1 and 120-2 may be fixed, but the voltage of the feedthrough 120 with respect to the vacuum enclosure 104, with respect to ground, or the like may vary. In some embodiments, only a single feedthrough 120 may be used for multiple getters 106. For example, the feedthrough 120-2 may be omitted, and an electrical connection to the vacuum enclosure 140 may be made instead. In some embodiments, the use of a single getter with the same or similar capacity as multiple getters 106 may have a larger thermal mass. As a result, a larger current may be required to activate the single getter. The use of multiple getters 106 allows for the same or similar capacity without requiring a larger current.

[0036] In other embodiments, the heating elements 122 may be electrically connected in parallel. Referring to Figure 5B, each end of each heating element 122 may be electrically connected directly to feedthroughs 120-1 and 120-2. As a result, the voltage across each heating element 122 may be substantially the same, within variations due to the resistance of the electrical connections.

[0037] 6 is a block diagram of an apparatus including a modular getter with multiple electrical connections, according to some embodiments. The apparatus 100e can be similar to the apparatus 100 described herein. However, the apparatus 100e includes multiple individual getters 106 or groups of getters 106 that are individually addressable.

[0038] In this example, three feedthroughs 120 extend through the first portion 102a of the support structure 102. The heating elements 122-1 and 122-2 of the getters 106-1 and 106-2 are electrically connected in series between the feedthroughs 120-2 and 120-3, respectively. The heating element 122-3 of the getter 106-3 is electrically connected between the feedthroughs 120-1 and 120-3. As a result, the heating element 122-3 can be activated independently of the heating elements 120-1 and 120-2. While the heating elements 122-1 and 122-2 can be activated as a group through the same feedthroughs 120-2 and 120-3, in other embodiments, each heating element 122 may be electrically connected to its own feedthrough 120. Additionally, although each of the heating elements 122 share a common feedthrough 120-3, in other embodiments, each individual heating element 122 or group of heating elements 122 may be electrically connected to a unique corresponding feedthrough 120.

[0039] In some embodiments, one or more getters 106 may not be electrically connected to any feedthroughs 120. Getter 106-4 is one example of such a getter 106. By way of example, only one getter 106-4 is shown, but in other embodiments, there may be multiple getters 106-4 that are not electrically connected to a feedthrough 120. Such getters 106 may be activated in ways other than electrically, such as during a thermal process, such as an inductive or optical (e.g., laser) bake-out operation through a vacuum enclosure 140, or the like.

[0040] 7 is a block diagram of an apparatus including a modular getter with shielding, according to some embodiments. Apparatus 100f can be similar to apparatus 100 described herein. However, apparatus 100f includes shielding 130. Shielding 130 is electrically connected to a vacuum enclosure 140.

[0041] In some embodiments, apparatus 100f includes an electron emitter 172. Electron emitter 172 is to be used as one example of a component disposed inside vacuum enclosure 140. Other examples include an anode, grid, electrode, or the like. Any of these structures may be at a high voltage relative to vacuum enclosure 140, support structure 102, getter 106, or the like. Thus, high electric fields may be generated that may cause arcing, high voltage instabilities, or the like.

[0042] The shielding material 130 is disposed between the getter 106 and the electron emitter 172 or another component that is not at the same potential as the getter 106. Thus, the strength of the electric field near the getter 106 can be reduced. The shielding material includes an opening 130a. The shielding material 130 may include multiple openings 130a. The openings 130a allow atoms or molecules to pass through the shielding material 130 and be captured by the getter 106.

[0043] In some embodiments, the getter 106 may not be located within a structure of the vacuum enclosure 140 that protrudes from the vacuum enclosure 140 to the exterior 140a. As a result, the getter 106 may be subject to a higher electric field than would otherwise be the case if the getter 106 were located within that protrusion. The shielding material 130a can reduce the strength of the electric field near the getter 106.

[0044] Eliminating protrusions may reduce the size, cost, or the like of the assembly 100f. For example, the overall size of the device 100f may be reduced. The size of the casing around the device 100f may be reduced. Thus, the device 100f may be placed closer to other components. Additionally, more costly materials such as leads may be reduced, reducing overall costs.

[0045] 8 is a block diagram of an apparatus including multiple modular getters, according to some embodiments. In some embodiments, apparatus 100g can be similar to apparatus 100 described herein. However, apparatus 100g includes multiple modular getters, which are shown here with corresponding multiple support structures 102. In this example, two support structures 102 having multiple getters 106 (not shown) are disposed within vacuum enclosure 140, each similar to support structure 102 having getters 106 described above.

[0046] The support structure 102 is disposed at the distal end of the vacuum enclosure in the X-axis. At each end, a shield 130 having an opening 130a separates the support structure 102 and getter 106 from structures such as an electron emitter 172, an anode 173, or the like. In some embodiments, the shield 130 is a metal or conductive plate attached to the vacuum enclosure 140. The opening 130a may comprise a gap between the metal or conductive plate and the wall of the vacuum enclosure 140.

[0047] In some embodiments, the electron emitter 172 may include multiple field emitters, such as carbon nanotube emitters. Field emitters may be more sensitive to vacuum levels. For example, an x-ray source without field emitters may have a 10 -7 ~10 -8 torr(1.33 -7 ~1.33 -8 They can operate at vacuum levels on the order of 10 kPa (100 psi) and maintain sufficient reliability, lifetime, or the like. However, due to the construction of the field emitter, the operating vacuum level must be approximately 10 kPa for similar reliability, lifetime, or the like. -8 ~10 -9 torr(1.33 -8 ~1.33 -9The vacuum level can be an order of magnitude smaller (an order of magnitude smaller) or even a hundred times smaller. For example, 10 -7 ~10 -8 torr(1.33 -7 ~1.33 -8 A vacuum level of the order of 10 kPa can be achieved using getter 106 (or additional getter 106). -8 ~10 -9 torr(1.33 -8 ~1.33 -9 The pressure can be reduced to a vacuum level of 0.5 kPa.

[0048] Shielding material 130 may be positioned based on a relative voltage difference. In some embodiments, anode 173 may be at a high voltage relative to getter 106 on support structure 102. Getter 106 and electron emitter 172 may both be at ground or at a relative voltage difference that may not result in arcing. Thus, shielding material 130 may be positioned between getter 106 and anode 173. In other embodiments, such as in a dual-ended configuration, both anode 173 and electron emitter 172 may be at a voltage that may be relatively large in magnitude relative to the voltage of getter 106.

[0049] 9 is a block diagram of an x-ray source having multiple getters, according to some embodiments. The apparatus 100h includes a vacuum enclosure and an electron emitter 172 similar to those described above. A plurality of different types of getters 106 are disposed within the vacuum enclosure 140. The materials of the getters 106 are different. At least one of the getters 106 has a material that is different from the material of another of the getters 106.

[0050] In some embodiments, the getters 106 may have different activation temperatures. For example, the first getter 106-1 may be configured to activate at a temperature used during a bakeout operation of the apparatus 100h. The bakeout may be one of many thermal treatments of the apparatus 100h. One example of such a temperature is about 400 degrees Celsius (°C) or less. However, the getter 106-2 may be activated at a higher temperature, such as above 400°C. While 400°C has been used as an example of a temperature between the activation temperatures of the getters 106-1 and 106-2, in other embodiments, a different temperature or temperature range may exist between the activation temperatures of 106-1 and 106-2. The bakeout operation temperature may be at that temperature or within that temperature range. As a result, the capacity of the getter 106-1 may be used during the bakeout operation and subsequent processing, while the capacity of the getter 106-2 may not be used because it is not activated.

[0051] Getter 106-2 may be activated differently, such as by Joule heating through electrical connection 150 through feedthrough 120, including using features similar to heating element 122 described above. After bakeout is complete, the capacity of getter 106-1 may be depleted, possibly to the full capacity of getter 106-1. Getter 106-2 may be activated at a later time, such as before transport, before vacuum pinch-off, or the like. As a result, the capacity of getter 106-2 may last throughout the lifetime of device 100h.

[0052] In some embodiments, at least one of the getters 106 is not electrically connected to the feedthrough 120. Additionally, at least one of the getters 120 is electrically connected to the feedthrough 120. Thus, at least one getter 106 may be electrically activated, while another getter 106 may be activated by other mechanisms, such as ambient temperature, local temperature, inductive or optical energy transfer through the vacuum enclosure, or the like.

[0053] In some embodiments, different materials of getter 106 may allow for trapping different atoms or molecules. Examples of different materials of getter 106 include tantalum, zirconium, titanium, aluminum, magnesium, thorium, alloys such as barium zirconia, titanium molybdenum, titanium salicide, or the like.

[0054] 10A and 10B are flowcharts of a technique for fabricating an apparatus according to some embodiments. Referring to FIG. 10A, the apparatus 100h of FIG. 9 will be used as an example to explain the operations at 1000. Referring to FIGS. 9 and 10A, in some embodiments, at 1002, a vacuum enclosure 140 may be provided. The vacuum enclosure, if provided, may have substantially all components other than the getter 106 and associated support structure 102. However, in other embodiments, some components may be installed later.

[0055] At 1004, a plurality of getters 106 are installed within the vacuum enclosure 140. The getters 106 may be any of the getters 106 described above, where the material of at least one of the getters 106 is different from the material of at least one other of the getters 106. The difference in materials may result in differences in activation technique (i.e., Joule heating, laser heating, radiative heating, induction heating, or the like), preferred atomic or molecular species, species set, activation temperature, or the like. The getters 106 may be installed by inserting the support structure 102 containing the getters 106 into the opening 140c of the vacuum enclosure. The support structure 102 may then be welded to the vacuum enclosure 140.

[0056] At 1005, a vacuum below a threshold is established within the vacuum enclosure. For example, the threshold is 10 -5 torr(1.33 -5 kPa), 10 -7 torr(1.33 -7kPa), or smaller; however, in other embodiments, the threshold may be different.

[0057] In 1006, a group of getters 106 are activated. For example, as described in more detail below, in some embodiments, various operations may be performed using a vacuum enclosure 140. Some getters 106 may be activated by ambient heat during operation. Some getters 106 may be activated by Joule heating through the feedthroughs 120. In some embodiments, some getters 106 may be adjacent to a structure that may be locally heated. For example, an anode outgassing operation may be performed by directing an electron beam toward the anode. As a result, the temperature of the anode and the localized area increases. The increased temperature of the localized area may be sufficient to activate adjacent getters 106. Regardless of how they are activated, fewer than all getters 106 are activated, leaving at least some getters 106 in an unactivated state.

[0058] At 1009, the vacuum enclosure 1010 is pinched off. The vacuum level is adjusted to approximately 10 -8 ~10 -9 torr(1.33 -8 ~1.33 -9The pressure may be varied until it stabilizes at a desired level, such as 100 kPa (100 psi). At 1010, the second group of getters 106 that were not activated along with the first group of getters 106 at 1006 are then activated. For example, the previously unactivated getters 106 may be activated through Joule heating using the feedthrough 120. As a result of waiting until after pinching off the vacuum enclosure 140, a large portion of the capacity of at least one of the unactivated getters 106 remains. Substantially all of the capacity may remain because the previously activated getter 106 may have captured a sufficient amount of atoms or molecules within the vacuum enclosure 140 to reach the desired vacuum level.

[0059] For a number of reasons, the vacuum level within vacuum enclosure 140 may decrease over time. Activation of the second group of getters 106 may occur later in the lifetime of device 100h. Additionally, activation of other groups of getters may be performed after pinch-off at 1009, at different times, and with different groups of getters. As a result, capacity of getters 106 may remain to capture atoms or molecules present later in the lifetime of device 100h. The getters 106 that are left for later activation may be selected based on the expected types of atoms or molecules that may appear within vacuum enclosure 140 during its lifetime.

[0060] 10B, in some embodiments, the operations at 1000′ can be similar to the operations at 1000 described above with respect to FIG. 10A. At 1007, operations can be performed with the vacuum enclosure 140. Examples of such operations include bakeout operations, activation of the first group of getters 106, conditioning and seasoning of the vacuum enclosure 140 and components, or the like.

[0061] In some embodiments, activation of the first group of getters 106 in 1006 and operation in 1007 may generate a significant amount of atoms or molecules that need to be removed from the vacuum enclosure 140. A pumping system can be used to pump the atoms or molecules out. However, some atoms or molecules may be difficult to remove using a pump. For example, hydrogen gas may be difficult to remove. The first group of getters 106 may be selected to favor hydrogen. The first group of getters 106 may be activated by the operation itself. In one particular example, heat from the bake-out operation may produce a temperature of approximately 400-500°C. That temperature may correspond to the activation temperature of the first group of getters 106.

[0062] In some embodiments, the third group of getters 106 that were not activated may be activated at 1008 prior to pinching off the vacuum at 1009. For example, bakeout, conditioning, performance testing, and the like may all be completed before activating the third group of getters at 1008. The third group of getters 106 may be activated. As part of the activation, any resulting atoms or molecules may be removed, such as by a turbo pump, prior to pinching off at 1009. Removal of atoms or molecules may be performed until the desired vacuum level is achieved. After pinching off the vacuum enclosure 140 at 1009, pumping may be discontinued.

[0063] FIG. 11 is a block diagram of an x-ray imaging system according to some embodiments. The x-ray imaging system 1100 includes an x-ray source 1102 and a detector 1110. The x-ray source 1102 may include the apparatus 100 described above or similar. In some embodiments, the x-ray source 1102 includes multiple field emitters (FE) 1124. An electron beam from the field emitter 1124 can be directed toward an anode 1126 to generate x-rays 1120. The x-ray source 1102 is positioned relative to the detector 1110 so that the x-rays 1120 can be generated as they pass through the sample 1122 and detected by the detector 1110. In some embodiments, the detector 1110 is part of a medical imaging system. In other embodiments, the x-ray imaging system 1100 may include a portable vehicle scanning system as part of a cargo scanning system. The system 1100 may be any system that may include an x-ray detector.

[0064] Some embodiments include an apparatus comprising: a vacuum enclosure 140 having an opening; a support structure 102 disposed within the vacuum enclosure 140, the support structure 102 having a first portion 102a attached to the vacuum enclosure 140 at the opening; and a second portion 102b extending within the vacuum enclosure 140; and a plurality of getters 106 disposed on the second portion 102b of the support structure 102.

[0065] In some embodiments, the device further comprises at least one elastic component 110; the movement of each of the getters 106 is at least partially constrained by a corresponding one of the at least one elastic component 110.

[0066] In some embodiments, for at least one of the getters 106, the getter 106 has a first end adjacent to a corresponding rigid component 108 of the support structure 102 and a second end adjacent to a corresponding one of the at least one elastic component 110; the getter 106 is in contact with the support structure 102 at the first end; and the getter 106 is offset from the support structure 102 at the second end.

[0067] In some embodiments, the support structure 102 has at least one rigid component 108 ; each of the getters 106 is constrained by a corresponding one of the at least one rigid component 108 .

[0068] In some embodiments, the support structure 102 has an extendible structure.

[0069] In some embodiments, the device further comprises a plurality of feedthroughs 120 extending through the first portion 102 a of the support structure 102 ; at least one of the getters 106 is electrically connected to the feedthroughs 120 .

[0070] In some embodiments, at least two of the getters 106 are electrically connected to the feedthrough 120 in series.

[0071] In some embodiments, at least two of the getters 106 are electrically connected to the feedthroughs 120 in parallel.

[0072] In some embodiments, at least two of the getters 106 are electrically accessible through the feedthroughs 120 .

[0073] In some embodiments, at least one of the getters 106 is not electrically accessible through the feedthrough 120 .

[0074] In some embodiments, at least two of the getters 106 that are electrically accessible through a feedthrough 120 are electrically accessible through the same feedthrough 120 .

[0075] In some embodiments, the getter 106 disposed on the support structure 102 is insertable into the opening from outside the vacuum enclosure 140 .

[0076] In some embodiments, the apparatus further comprises an electron emitter 172 disposed within the vacuum enclosure 140; a shielding material 130 electrically connected to the vacuum enclosure 140 and disposed between the electron emitter and the getter 106.

[0077] In some embodiments, the shielding material 130 has multiple openings.

[0078] In some embodiments, the electron emitter 172 comprises multiple field emitters.

[0079] In some embodiments, a first one of the first type of getters 106 is different from a second one of the second type of getters 106; the first type comprises a first material; the second type comprises a second material; and the first material is different from the second material.

[0080] Some embodiments include a method comprising the steps of: providing a support structure 102 including a first portion 102a and a second portion 102b; mounting a plurality of getters 106 on the second portion 102b of the support structure 102; inserting the support structure 102 having the getters 106 into an opening in a vacuum enclosure 140; and attaching the first portion 102a of the support structure 102 to the vacuum enclosure 140 at the opening.

[0081] In some embodiments, the step of inserting the support structure 102 having the getter 106 into the opening of the vacuum enclosure 140 includes inserting the support structure 102 having the getter 106 into the opening of the vacuum enclosure 140 from outside the vacuum enclosure 140.

[0082] In some embodiments, mounting the getters 106 on the second portion 102 b of the support structure 102 includes constraining at least one of the getters 106 between a rigid component 108 and an elastic component 110 .

[0083] In some embodiments, the method further comprises extending the second portion 102 b of the support structure 102 .

[0084] In some embodiments, the method further comprises electrically connecting at least one of the getters 106 to a feedthrough 120 that passes through the first portion 102 a of the support structure 102 .

[0085] In some embodiments, the method further comprises electrically disconnecting at least one of the getters 106 .

[0086] In some embodiments, the method further comprises electrically connecting at least two of the getters 106 in series.

[0087] In some embodiments, the method further comprises electrically connecting at least two of the getters 106 in parallel.

[0088] In some embodiments, the method further comprises the steps of: placing an electron emitter in a vacuum enclosure 140; and placing a shielding material 130 between the electron emitter and the getter 106, the shielding material 130 being electrically connected to the vacuum enclosure 140.

[0089] Some embodiments include an apparatus comprising a vacuum enclosure 140; and a plurality of getters 106 disposed within the vacuum enclosure 140; wherein a first of a first type of getters 106 is different from a second of a second type of getters 106; the first type comprises a first material; the second type comprises a second material; and the first material is different from the second material.

[0090] In some embodiments, the activation temperature of the first type is different from the activation temperature of the second type.

[0091] In some embodiments, the device further comprises a plurality of feedthroughs 120 penetrating the vacuum enclosure 140; at least one of the getters 106 is electrically connected to the feedthrough 120; and at least one of the getters 106 is not electrically connected to the feedthrough 120.

[0092] In some embodiments, the apparatus further comprises a support structure 102 disposed within a vacuum enclosure 140, the support structure 102 having a first portion 102a attached to the vacuum enclosure 140 at an opening within the vacuum enclosure 140; and a second portion 102b extending within the vacuum enclosure 140; and the getter 106 disposed on the second portion 102b of the support structure 102.

[0093] Some embodiments include a method comprising: providing a vacuum enclosure 140; placing a plurality of getters 106 inside the vacuum enclosure 140, wherein a first one of a first type of getters 106 is different from a second one of a second type of getters 106; the first type comprises a first material; the second type comprises a second material; and the first material is different from the second material; establishing a vacuum below a threshold value within the vacuum enclosure 140; activating a first group of getters 106 after establishing a vacuum below the threshold value within the vacuum enclosure 140; pinching off the vacuum enclosure 140; and activating a second group of getters 106 that are different from the first group of getters 106, such that after pinching off the vacuum enclosure 140, most of the capacity of the second group of getters 106 remains.

[0094] In some embodiments, the method further comprises performing an operation with the vacuum enclosure 140 after activating the first group of getters 106 and before pinching off the vacuum enclosure 140 .

[0095] In some embodiments, the method further comprises activating a third group of getters 106 different from the first group of getters 106 and the second group of getters 106 after performing the operation and before pinching off the vacuum enclosure 140.

[0096] In some embodiments, activating the first group of getters 106 further comprises activating the first group of getters 106 using heat from operation.

[0097] Some embodiments include an apparatus comprising: a means for enclosing a vacuum; a plurality of means for trapping atoms or molecules disposed within the means for enclosing a vacuum; a means for supporting the plurality of means for trapping atoms or molecules; and a means for attaching the means for supporting the plurality of means for trapping atoms or molecules to the means for enclosing a vacuum.

[0098] An example of a means for enclosing a vacuum includes a vacuum enclosure 140. An example of a plurality of means for trapping atoms or molecules includes a getter 106. Examples of a means for supporting a plurality of means for trapping atoms or molecules include a support structure 102 and its various components, a rigid structure 108, an elastic structure 110, or the like. Examples of a means for attaching a means for supporting a plurality of means for trapping atoms or molecules to a means for enclosing a vacuum include an opening 140a, a first portion 102a of the support structure 102, and the techniques described above for attaching structures.

[0099] In some embodiments, the apparatus further comprises at least one of: means for selectively activating the plurality of means for trapping atoms or molecules; means for shielding the plurality of means for trapping atoms or molecules; and means for electrically connecting to at least one of the plurality of means for trapping atoms or molecules.

[0100] Examples of means for selectively activating a plurality of means for trapping atoms or molecules include feedthroughs 120, heating elements 122, associated electrical connections, or the like.

[0101] Examples of means for shielding the plurality of means for trapping atoms or molecules include a shielding material 130, a conductive plate 107, or the like.

[0102] Examples of means for electrically connecting to at least one of the means for trapping atoms or molecules include a feedthrough 120, an associated electrical connection, or the like.

[0103] Some embodiments include an apparatus comprising: means for enclosing a vacuum; and a plurality of means for trapping atoms or molecules disposed within the means for enclosing a vacuum; wherein a first of a first type of the plurality of means for trapping atoms or molecules is different from a second of a second type of the plurality of means for trapping atoms or molecules; the first type comprises a first material; the second type comprises a second material; and the first material is different from the second material.

[0104] An example of a means for enclosing a vacuum includes a vacuum enclosure 140. An example of a means for capturing atoms or molecules disposed within the means for enclosing a vacuum includes a getter 106.

[0105] In some embodiments, the apparatus further comprises at least one of: means for performing an operation with the means for enclosing a vacuum after activating the first type of plurality of means for trapping atoms or molecules and before pinching off the means for enclosing a vacuum; means for activating a third type of plurality of means for trapping atoms or molecules, different from the first type of plurality of means for trapping atoms or molecules and the second type of plurality of means for trapping atoms or molecules, after performing an operation with the means for enclosing a vacuum after activating the first type of plurality of means for trapping atoms or molecules and before pinching off the means for enclosing a vacuum; and means for activating the first type of plurality of means for trapping atoms or molecules using heat from an operation performed with the means for enclosing a vacuum after activating the first type of plurality of means for trapping atoms or molecules and before pinching off the means for enclosing a vacuum.

[0106] Examples of means for performing an operation with the means for enclosing a vacuum after activating the first type of plurality of means for trapping atoms or molecules and before pinching off the means for enclosing a vacuum include electron emitter 172, anode 173, the various pumps described above, or the like.

[0107] Examples of means for activating a third type of plurality of means for trapping atoms or molecules, different from the first type of plurality of means for trapping atoms or molecules and the second type of plurality of means for trapping atoms or molecules, after performing an operation with the means for enclosing a vacuum after activating the first type of plurality of means for trapping atoms or molecules and before pinching off the means for enclosing a vacuum include a feedthrough 120, a heating element 122, an induction heater, an optical heater, or the like.

[0108] Examples of means for activating a first type of plurality of means for trapping atoms or molecules using heat from an operation performed with the means for enclosing a vacuum after activating the first type of plurality of means for trapping atoms or molecules and before pinching off the means for enclosing a vacuum include electron emitters 172, anodes 173, the various pumps described above, or the like.

[0109] While structures, devices, methods, and systems according to specific embodiments have been described, those skilled in the art will readily recognize that many variations to the specific embodiments are possible, and therefore, any variations should be considered within the spirit and scope of what is disclosed herein. Accordingly, many modifications may be made by those skilled in the art without departing from the spirit and scope of what is set forth in the appended claims.

[0110] The claims that follow this written disclosure are hereby expressly incorporated into this written disclosure, with each claim standing on its own as a separate embodiment. The present disclosure includes all permutations of independent claims with their dependent claims. Furthermore, additional embodiments that are derivable from the following independent and dependent claims are also expressly incorporated into this written specification. These additional embodiments are determined by replacing the dependency of a given dependent claim with the phrase "any of the claims beginning with claim [x] and ending with the claim immediately preceding this claim," where the bracketed term "[x]" is replaced with the number of the most recently described independent claim. For example, with respect to a first set of claims beginning with independent claim 1, claim 4 may depend on either claims 1 and 3, and these separate dependencies result in two separate embodiments; claim 5 may depend on any one of claims 1, 3 or 4, and these separate dependencies result in three separate embodiments; claim 6 may depend on any one of claims 1, 3, 4 or 5, and these separate dependencies result in four separate embodiments; and so on.

[0111] The recitation in a claim of the term "first" with respect to a feature or element does not necessarily imply the presence of a second or additional such feature or element. Elements specifically described in means-plus-function form are intended to be construed to include the corresponding structure, material, or acts described herein, if present, and their equivalents under 35 U.S.C. §112(f). The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

Claims

1. a vacuum enclosure having an opening; a support structure disposed within the vacuum enclosure, the support structure comprising: a first portion attached to the vacuum enclosure at the opening; and a second portion extending within the vacuum enclosure; and a plurality of getters disposed on the second portion of the support structure; An apparatus comprising:

2. At least one elastic component Furthermore, 10. The apparatus of claim 1, wherein the movement of each of the plurality of getters is at least partially constrained by a corresponding one of the at least one elastic component.

3. For at least one of the plurality of getters, the getter having a first end adjacent a corresponding rigid component of the support structure and a second end adjacent the corresponding one of the at least one elastic component; the getter contacting the support structure at the first end; and 3. The device of claim 2, wherein the getter is offset from the support structure at the second end.

4. the support structure has at least one rigid component; and each of the plurality of getters is constrained by a corresponding one of the at least one rigid component; 10. The apparatus of claim 1.

5. The device of claim 1 , wherein the support structure comprises an extendable structure.

6. further comprising a plurality of feedthroughs extending through the first portion of the support structure; The apparatus of claim 1 , wherein at least one of the plurality of getters is electrically connected to the feedthrough.

7. At least two of the plurality of getters are electrically connected in series to the feedthrough; and / or 7. The apparatus of claim 6, wherein at least two of the plurality of getters are electrically connected to the feedthrough in parallel.

8. 7. The apparatus of claim 6, wherein at least two of said plurality of getters are electrically accessible through said feedthrough.

9. 9. The apparatus of claim 8, wherein at least one of the plurality of getters is not electrically accessible through the feedthrough.

10. 10. The apparatus of claim 1, wherein the plurality of getters disposed on the support structure are insertable into the opening from outside the vacuum enclosure.

11. an electron emitter disposed within the vacuum enclosure; and a shielding material electrically connected to the vacuum enclosure and disposed between the electron emitter and the getter; The apparatus of claim 1 further comprising:

12. The apparatus of claim 11 , wherein the electron emitter comprises a plurality of field emitters.

13. a first one of the plurality of getters of a first type is different from a second one of the plurality of getters of a second type; the first type includes a first material; the second type includes a second material; and the first material is different from the second material; 12. The apparatus of claim 11.

14. providing a support structure including a first portion and a second portion; mounting a plurality of getters on the second portion of the support structure; inserting the support structure with the getter into an opening in a vacuum enclosure; and attaching the first portion of the support structure to the vacuum enclosure at the opening A method comprising:

15. 15. The method of claim 14, wherein inserting the support structure having the getter into the opening of the vacuum enclosure comprises inserting the support structure having the getter into the opening of the vacuum enclosure from outside the vacuum enclosure.

16. 15. The method of claim 14, wherein mounting the getter on the second portion of the support structure comprises constraining at least one of the plurality of getters between a rigid component and a resilient component.

17. The method of claim 14 further comprising extending the second portion of the support structure.

18. 15. The method of claim 14, further comprising electrically connecting at least one of the plurality of getters to a feedthrough that passes through the first portion of the support structure.

19. means for enclosing a vacuum; a plurality of means for trapping atoms or molecules disposed within said means for enclosing said vacuum; means for supporting said plurality of means for capturing atoms or molecules; and means for attaching said means for supporting said plurality of means for trapping atoms or molecules to said means for enclosing said vacuum; An apparatus comprising:

20. means for selectively activating said plurality of means for capturing atoms or molecules; means for shielding said plurality of means for capturing atoms or molecules; and means for electrically connecting to at least one of said plurality of means for trapping atoms or molecules; 20. The apparatus of claim 19, further comprising at least one of:

Images